NOTES: DC-n are some of the earliest crystals
FT-n came next and superceded some DC-n numbers.
CR-n/U came last and often consisted of FT-241 or FT-243 holders marked for
and containing crystals cut for specific radios or radio sets.
(The "n" number may be one, two or three digits.)

CR-4/U is FT-241 holder marked for and containing crystals cut for
AN/TRC-1.

CF5 - Crystal by HIPOWER. This is a round crystal with 1-3/8" diameter X 5/8" thick.
It has two pins spaced 3/4" apart and approx. 3/16" diameter.
There are other variants of this round crystal with different names made by Bliley and others.
They are fairly scarce.

CHF-40130 - Navy style crystal holder for TCS receiver.
Large with 3 pins. Same as CR-15/U DImensions: 1-5/8" X
1-3/16" X 2-1/16" tall. The three pins are each 1/8" diameter
and 1/2" long.

CM-1 crystal holder is close in size to a DC-34, except for the pin diameter. The case is narrower on the CM-1.
The CM-1 is 1 - 7/32 in. wide, and the DC-34 is 1 - 3/8". The CM-1 pins are 1/8 in.( 0.125 in. ) diameter.

FT-164 - Ceramic Body Holder, adjustable contact. Dimensions: 2.25" diameter, 1.125" thick. Has two offset pins that protrude 0.5" long, and 0.25" diameter. Has a metal plate on the bottom. This is a very impressive-looking, and RARE crystal.

HC-11/U - same as CR-1A/AR - see above. As used in SCR-522 VHF transmitters etc.

HC-26/U - Same case body as FT-243 but with thicker (1/8")pins the same
as used in CR-1/A crystals. These were probably intended for use
in radios that used CR-1A crystals long after the CR-1A crystals
were no longer being manufactured. Still available in glass cases from
TFC in the U.K. at http://www.tfc.co.uk
See data sheet at:
http://www.tfc.co.uk/data_library/020-006-00_HC-26.pdf

Now Available!

I have around 100 nice clean quartz crystals made for
use in FT243 holders.These are a nice mix from about 1000 kHz up to 8500 kHz.
See photo below:
I will sell the whole bunch for $20.00 plus $6.00 for USA Shipping.

QST MAGAZINE for August 1925 had an advertisement from General Radio Company in Cambridge, Mass, offering quartz crystals finished to a specified frequency for $50.00 each. That was a LOT of money back then!

I am amazed to find out HOW MANY companies have had their
names on crystals over the years. Do you know of more?
These names will likely be lost to obscurity in a few years
if we do not somehow memorialize them here or in our publications.
I count over 110 companies so far, although I suspect some were
duplicate outfits operating under different names. many of these
firms had to have had their own machinery for making the crystals.
Most of these firms existed in the 1940-160 era, which was the heyday
of radio crystal manufacturing. Quite a short period of time, when
you think about it! You have to wonder what happened to all of these companies!

* - information on how Scientific Radio Co. came to be, is in the book:
"In Tune With Leo" by Leo Meyerson

# - Still in business as of 2012

ICM in 1950: Royden R. Freeland founds International Crystal
Manufacturing Company (ICM). and operates in his garage. He soon moved the company to a building in downtown Oklahoma City. One of the first major contracts he obtained was to produce crystals for Collins Radio. Soon, he was making crystals for many other communications companies. ICM also began manufacturing a line oscillators and converters for Ham and experimenter use. The product line grew and, by the late 1950s, included cable TV equipment, frequency meters, CB radios, Ham Radio kits, and quartz crystals.